I plan to use the $800K to buy mixed use retail/MF, or just MF property(ies) in Northern NJ/NYC 4 boroughs minus Staten Island. $800K would allow me to access $2.6M+ worth of RE. 2.

The only way you can mix any of those together is to be a real estate professional. 

Now you have thrown another item into this mix, a third lien.

However, I'm seeing lots of mixed opinions on what contracts to use.

Most commercial, mixed-use, office, multifamily res, and small industrial uses permitted. 

However, you can’t deduct any loss of rental income for the period the property is vacant.I’ve gotten mixed answers on what to do.

I ended up with an additional $131K credit on a sole proprietorship (they couldn't/wouldn't/didn't work with my existing LLC) across 4 cards, all with 0% APR for between 6-12 months with a mix of balance-transfer-only and purchase-and-balance-transfer restrictions.That being said, the results were less than exciting.

If your going to be mixing all of these accounts and then going for a self directed roth IRA later, this will apply to you. 

Here's a mix of steps and strategies that might help steer you through these choppy waters:Documentation Is Your Best Friend: Make sure you've got a solid paper trail of all interactions, notices, and agreements related to rent payments.

2) The ESA is Staffordshire terrier mix and comes in the aggressive breed.